Autonomous and heterogeneous network discovery and reuse

ABSTRACT

In some embodiments, a method is disclosed involving a mobile device discovery and use of target wireless networks which are at least partly within a coverage area of another wireless network which provides location information which includes: acquiring data from a plurality of said target wireless networks; acquiring location information from said another wireless network; mapping said data from said plurality of said target wireless networks with said location information; and selecting one of said plurality of target wireless networks based on said mapped data.

The present application is a divisional under 35 U.S.C. 120 of U.S.application Ser. No. 11/096,722, filed on Apr. 1, 2005, entitledAutonomous and Heterogeneous Network Discovery and Reuse, to R. Yaqub,et al., the entire disclosure of which is incorporated herein byreference.

BACKGROUND

1. Field of the Invention

The present application relates to wireless networking and, in somepreferred embodiments, to systems and methods for mobile stationsautonomous and heterogeneous network discovery and reuse, and, in somepreferred embodiments to the discovery of networks and informationregarding the networks, and, in some preferred embodiments, to methodsof using information acquired by autonomous discovery to supportproactive handover actions and/or the like.

2. General Background Discussion

Networks and Internet Protocol

There are many types of computer networks, with the Internet having themost notoriety. The Internet is a worldwide network of computernetworks. Today, the Internet is a public and self-sustaining networkthat is available to many millions of users. The Internet uses a set ofcommunication protocols called TCP/IP (i.e., Transmission ControlProtocol/Internet Protocol) to connect hosts. The Internet has acommunications infrastructure known as the Internet backbone. Access tothe Internet backbone is largely controlled by Internet ServiceProviders (ISPs) that resell access to corporations and individuals.

With respect to IP (Internet Protocol), this is a protocol by which datacan be sent from one device (e.g., a phone, a PDA [Personal DigitalAssistant], a computer, etc.) to another device on a network. There area variety of versions of IP today, including, e.g., IPv4, IPv6, etc.Each host device on the network has at least one IP address thatidentifies the host device's point of attachment to the IP networks.

IP is a connectionless protocol. The connection between end pointsduring a communication is not continuous. When a user sends or receivesdata or messages, the data or messages are divided into components knownas packets. Every packet is treated as an independent unit of data.

In order to standardize the transmission between points over theInternet or the like networks, an OSI (Open Systems Interconnection)model was established. The OSI model separates the communicationsprocesses between two points in a network into seven stacked layers,with each layer adding its own set of functions. Each device handles amessage so that there is a downward flow through each layer at a sendingend point and an upward flow through the layers at a receiving endpoint. The programming and/or hardware that provides the seven layers offunction is typically a combination of device operating systems,application software, TCP/IP and/or other transport and networkprotocols, and other software and hardware.

Typically, the top four layers are used when a message passes from or toa user and the bottom three layers are used when a message passesthrough a device (e.g., an IP host device). An IP host is any device onthe network that is capable of transmitting and receiving IP packets,such as a server, a router or a workstation. Messages destined for someother host are not passed up to the upper layers but are forwarded tothe other host. In the OSI and other similar models, IP is in Layer-3,the network layer.

Wireless Networks

Wireless networks can incorporate a variety of types of mobile devices,such as, e.g., cellular and wireless telephones, PCs (personalcomputers), laptop computers, wearable computers, cordless phones,pagers, headsets, printers, PDAs, etc. For example, mobile devices mayinclude digital systems to secure fast wireless transmissions of voiceand/or data. Typical mobile devices include some or all of the followingcomponents: a transceiver (i.e., a transmitter and a receiver,including, e.g., a single chip transceiver with an integratedtransmitter, receiver and, if desired, other functions); an antenna; aprocessor; one or more audio transducers (for example, a speaker or amicrophone as in devices for audio communications); electromagnetic datastorage (such as, e.g., ROM, RAM, digital data storage, etc., such as indevices where data processing is provided); memory; flash memory; a fullchip set or integrated circuit; interfaces (such as, e.g., USB, CODEC,UART, PCM, etc.); and/or the like.

Wireless LANs (WLANs) in which a mobile user can connect to a local areanetwork (LAN) through a wireless connection may be employed for wirelesscommunications. Wireless communications can include, e.g.,communications that propagate via electromagnetic waves, such as light,infrared, radio, microwave. There are a variety of WLAN standards thatcurrently exist, such as, e.g., Bluetooth, IEEE 802.11, and HomeRF.

By way of example, Bluetooth products may be used to provide linksbetween mobile computers, mobile phones, portable handheld devices,personal digital assistants (PDAs), and other mobile devices andconnectivity to the Internet. Bluetooth is a computing andtelecommunications industry specification that details how mobiledevices can easily interconnect with each other and with non-mobiledevices using a short-range wireless connection. Bluetooth creates adigital wireless protocol to address end-user problems arising from theproliferation of various mobile devices that need to keep datasynchronized and consistent from one device to another, thereby allowingequipment from different vendors to work seamlessly together. Bluetoothdevices may be named according to a common naming concept. For example,a Bluetooth device may possess a Bluetooth Device Name (BDN) or a nameassociated with a unique Bluetooth Device Address (BDA). Bluetoothdevices may also participate in an Internet Protocol (IP) network. If aBluetooth device functions on an IP network, it may be provided with anIP address and an IP (network) name. Thus, a Bluetooth Device configuredto participate on an IP network may contain, e.g., a BDN, a BDA, an IPaddress and an IP name. The term “IP name” refers to a namecorresponding to an IP address of an interface.

An IEEE standard, IEEE 802.11, specifies technologies for wireless LANsand devices. Using 802.11, wireless networking may be accomplished witheach single base station supporting several devices. In some examples,devices may come pre-equipped with wireless hardware or a user mayinstall a separate piece of hardware, such as a card, that may includean antenna. By way of example, devices used in 802.11 typically includethree notable elements, whether or not the device is an access point(AP), a mobile station (STA), a bridge, a PCMCIA card or another device:a radio transceiver; an antenna; and a MAC (Media Access Control) layerthat controls packet flow between points in a network.

In addition, Multiple Interface Devices (MIDs) may be utilized in somewireless networks. MIDs may contain two independent network interfaces,such as a Bluetooth interface and an 802.11 interface, thus allowing theMID to participate on two separate networks as well as to interface withBluetooth devices. The MID may have an IP address and a common IP(network) name associated with the IP address.

Wireless network devices may include, but are not limited to Bluetoothdevices, Multiple Interface Devices (MIDs), 802.11x devices (IEEE 802.11devices including, e.g., 802.11a, 802.11b and 802.11g devices), HomeRF(Home Radio Frequency) devices, Wi-Fi (Wireless Fidelity) devices, GPRS(General Packet Radio Service) devices, 3G cellular devices, 2.5Gcellular devices, GSM (Global System for Mobile Communications) devices,EDGE (Enhanced Data for GSM Evolution) devices, TDMA type (Time DivisionMultiple Access) devices, or CDMA type (Code Division Multiple Access)devices, including CDMA2000. Each network device may contain addressesof varying types including but not limited to an IP address, a BluetoothDevice Address, a Bluetooth Common Name, a Bluetooth IP address, aBluetooth IP Common Name, an 802.11 IP Address, an 802.11 IP commonName, or an IEEE MAC address.

Wireless networks can also involve methods and protocols found in, e.g.,Mobile IP (Internet Protocol) systems, in PCS systems, and in othermobile network systems. With respect to Mobile IP, this involves astandard communications protocol created by the Internet EngineeringTask Force (IETF). With Mobile IP, mobile device users can move acrossnetworks while maintaining their IP Address assigned once. See Requestfor Comments (RFC) 3344. NB: RFCs are formal documents of the InternetEngineering Task Force (IETF). Mobile IP enhances Internet Protocol (IP)and adds means to forward Internet traffic to mobile devices whenconnecting outside their home network. Mobile IP assigns each mobilenode a home address on its home network and a care-of-address (CoA) thatidentifies the current location of the device within a network and itssubnets. When a device is moved to a different network, it receives anew care-of address. A mobility agent on the home network can associateeach home address with its care-of address. The mobile node can send thehome agent a binding update each time it changes its care-of addressusing, e.g., Internet Control Message Protocol (ICMP).

In basic IP routing (i.e. outside mobile IP), typically, routingmechanisms rely on the assumptions that each network node always has aconstant attachment point to, e.g., the Internet and that each node's IPaddress identifies the network link it is attached to. In this document,the terminology “node” includes a connection point, which can include,e.g., a redistribution point or an end point for data transmissions, andwhich can recognize, process and/or forward communications to othernodes. For example, Internet routers can look at, e.g., an IP addressprefix or the like identifying a device's network. Then, at a networklevel, routers can look at, e.g., a set of bits identifying a particularsubnet. Then, at a subnet level, routers can look at, e.g., a set ofbits identifying a particular device. With typical mobile IPcommunications, if a user disconnects a mobile device from, e.g., theInternet and tries to reconnect it at a new subnet, then the device hasto be reconfigured with a new IP address, a proper netmask and a defaultrouter. Otherwise, routing protocols would not be able to deliver thepackets properly.

Network Discovery

In the evolution of wireless networking based on, e.g., wireless LAN(Local Area Network) and cellular technologies, and as mobility servicesprevail and people become increasingly mobile, it is more important fora mobile device to be able to find an appropriate point of networkattachment that meets the application requirements and thecharacteristics of the mobile, in a timely, accurate and efficientmanner. In this disclosure, this functionality is referred to as networkdiscovery.

In this regard, network discovery can relate to, e.g., the discovery ofinformation that the mobile station uses to access a network, such as,by way of example, a network attachment point identification (e.g., anL2 address and/or a geographical address of an access point), a MAC type(e.g., “IEEE 802.11g”) of an access point, a security type (e.g., “WPA”or “PANA and IPsec”) supported by an access point, a layer-3 type (e.g.,“IPv4 only” or “IPv4/v6 dual stack”), a provider name, or the addressesof a server or an agent (e.g., PANA authentication agents, accessrouters, SIP servers and Mobile IP home agents).

While a variety of wireless systems and methods are known, there remainsa need for improved systems and methods, related to, among other things,network discovery and reuse.

SUMMARY OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention can significantlyimprove upon existing methods and/or apparatuses.

The preferred embodiments relate to new methods for a mobile station(MS) to autonomously discover the existence of networks and informationregarding the networks. For example, the MS functions without assistancefrom other MSs or from network information servers. The informationacquired by autonomous discovery is used to support proactive handoveractions.

In one embodiment of the invention, a mobile station autonomouslydiscovers the existence of networks and data regarding the networks in acellular network. Upon entering into a cellular cell area, data isacquired from at least one a target network, and most typically, from aplurality of target networks. A list of acquired target networks isgenerated and is retained upon exiting said cellular cell area. In thisdisclosure, the terminology “list” encompasses not only the illustratedand described exemplary tables herein, but any manner of maintainingdata, which can include, e.g., any form of digital or computer storageor memory, any format of storage, such as, e.g., within tables,spreadsheets, relational databases and/or any other arrangement of datastorage. When the mobile station re-enters a cellular cell area, theacquired data from the list is used to determine which networks arewithin the cell area. Where a cellular cell area has a plurality ofWLANs the list is populated with data from the plurality of WLANs. Usingthe data in the list, the most suitable WLAN can be selected from thelist of a plurality of WLANs, based on predetermined criteria.

The data acquired by autonomous discovery is preferably used to supportproactive handover actions. The method of supporting proactive handovercan include the steps of selecting the most suitable WLAN from said listof a plurality of WLANs, based on predetermined criteria. The method caninclude the step of performing pre-authentication with the targetnetwork. In another embodiment of the invention the method can includethe step of obtaining a local IP address from a target network uponentering into said cell area.

In another embodiment of the invention, in which there are pluralitiesof WLANs within a cell area, the list of known networks can be mappedwith location data received from the cellular network.

In another embodiment of the invention, upon entering into a subsequentcellular cell area, data is acquired from at least one a target networkwithin the subsequent cell area. A list of acquired target networkswithin the subsequent cell area is maintained and retained said listupon exiting the subsequent cellular cell area, such that the listcomprises data from a plurality of different cell areas.

In another embodiment of the invention, the mobile station performsproactive handover actions of a selected candidate network. Thepro-active handover can include the steps of anticipating the need for ahandover, selecting the most suitable network from the list of acquiredtarget networks, based on predetermined criteria using of available datafrom said list, and thereafter handing over to a selected candidatenetwork when the need arises to handover from one network to anothernetwork.

In another embodiment of the invention, WLAN broadcasts are monitoredand parameters mapped with LAI and CGI are stored in the list. Thestored data in the list can include signal strength and time ofacquisition.

In another embodiment of the invention, the method can include the stepsof:

-   -   1) recording a recent history of movements of a mobile station;    -   2) recording the WLANs traversed in the movement pattern from a        first cell area to subsequent cell areas;    -   3) storing data about recorded WLANs specifically mapped with        LAI and CGI;    -   4) down selecting the most suitable candidate network (e.g.,        based on CGI during a current session);    -   5) acquiring a local IP address from the down selected most        suitable candidate network;    -   6) performing pre-authentication with the selected network;    -   7) making the selected network available for a prospective        handover; and    -   8) recording a log of performance of networks used.

In some examples, the embodiment can further comprise the steps of auser of said mobile station selecting priority parameters for theselection of a candidate network from the available candidate networks,and storing in said mobile station, the user's selected priorityparameters.

In another embodiment of the invention, data in said list is sortedbased on the user's preferred selection criteria and priority selectionweights are assigned to the sorted data such that preferred selectioncriteria data has greater selection weights than non-preferred selectedcriteria data. The embodiment can include the step of selecting an SSIDbased on the user's selected priority parameters.

In another embodiment of the invention, a method of a mobile stationautonomously discovering the existence of networks and data regardingthe networks in a cellular network, can comprise the steps of: uponentering into a cellular cell area, acquiring data from a plurality oftarget networks; storing a list of acquired target networks, andselecting a target network from a plurality of target networks withinsaid cell area; and selecting a target WLAN based on weights assigned toknown WLANs in accordance with probability P_(j) which is calculated asfollows:

$p_{j} = \frac{W_{j}}{\sum\limits_{i = 1}^{k}W_{i}}$where W=assigned weight value, P_(j)=probability, k=number of WLANSwithin said mobile station's current cell area, W_(i)=the weightassigned to WLAN i, and W_(j)=the weight assigned to WLAN j.

The above and/or other aspects, features and/or advantages of variousembodiments will be further appreciated in view of the followingdescription in conjunction with the accompanying figures. Variousembodiments can include and/or exclude different aspects, featuresand/or advantages where applicable. In addition, various embodiments cancombine one or more aspect or feature of other embodiments whereapplicable. The descriptions of aspects, features and/or advantages ofparticular embodiments should not be construed as limiting otherembodiments or the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention are shown by a way ofexample, and not limitation, in the accompanying figures, in which:

FIG. 1 is a schematic representation of multiple cells and each cell isidentified by an identification Cell Global identity;

FIG. 2 is a schematic representation of the selection of a WLAN from acell of a cellular system in which four WLANs (WLAN-1, WLAN-2, WLAN-3,and WLAN-4) are operating;

FIG. 3 is a flow diagram of the method of populating a table withoutconnecting to a network;

FIG. 4 is a flow diagram of the method of populating a table whileconnected to a network; and

FIG. 5 is schematic diagram depicting an example of a table storing,e.g., mapped network parameters and some processes used to construct thetable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention may be embodied in many different forms, anumber of illustrative embodiments are described herein with theunderstanding that the present disclosure is to be considered asproviding examples of the principles of the invention and that suchexamples are not intended to limit the invention to preferredembodiments described herein and/or illustrated herein.

Seamless integration of heterogeneous wireless networks is a major steptowards a new generation of wireless networks. In this regard,heterogeneous networks can include, e.g., different networks or networkshaving one or more dissimilarities. Achieving seamless integration ofheterogeneous wireless networks requires capabilities to supportseamless handover and mobility management to enable ubiquitous servicesacross heterogeneous Radio Access Technologies (RATs). To supportseamless handover across heterogeneous RATs, a system should preferablyhave the following notable capabilities:

1. Quick network discovery: To discover the existence of networks andinformation regarding the networks that a mobile station (“MS” or“mobile”) will handover to;

2. Down selection of candidate networks: When multiple networks areavailable at the same time, a MS should preferably quickly select onenetwork to use; and

3. Proactive handover: A MS may perform proactive handover actionsbefore it actually hands over into a target network to reduce handoverdelay. For example, the MS may pre-acquire a local IP address from,and/or conduct pre-authentication with, a target network.

In an example of the invention, there is a MS with multiple radionetwork interfaces, such as a wireless Local Area Network (WLAN)interface and a cellular network interface (such as, e.g., GPRS,cdma2000, GSM), a geographical region that is covered by cellularservices and WLANs are also available in the region. WLANs may not coverthe entire region, but their coverage areas can overlap. When a MS movesabout in this region, it may need to handover between WLANs, and betweena WLAN and the cellular network. When the mobile is covered by multipleWLANs simultaneously, it needs to select one WLAN to use if it decidesto use a WLAN.

Preferably, the MS establishes and maintains a list of availablenetworks, referred to as the “Known Networks”. When a MS receives radiosignals from a network or when the mobile connects to the network, themobile learns about the existence of the network and other informationabout the network that the mobile can use to prioritize the networks. Atthe same time, the MS uses the information available to it from itscellular network interface to help determine the locations of its KnownNetworks. This enables the MS to know, for example, which WLANs areinside a cell of the cellular network. The mobile maintains the list ofthe Known Networks mapped with the location information received fromthe cellular network and retains it even after it leaves these networks.This enables the MS to use the information to determine where thesenetworks are when the mobile comes back to the neighborhood in thefuture.

When the MS moves into a new cellular cell and there are multiple KnownWLANs in the cell, the MS selects the most suitable candidate WLAN fromthe Known WLANs in the cell. This process is referred to as “downselect”. Then, the MS can perform pro-active handover actions for theselected candidate network. Pro-active handover refers to the use ofavailable data in a pre-selection, in preparation for a handover. In apro-active handover, there is preparation for the need for a handoverand a pre-selection, as compared to processing handover determinationsafter the need arises. The pro-active handover actions include acquiringa local IP address from, or performing pre-authentication with, thetarget network. These proactive handover actions reduce handover delayand enable cellular subscribers to attain seamless service roamingacross several RATs including, e.g., WLANs, 3G or other evolving RATs.Thus, a user can benefit from high throughput IP connectivity availablein the footprint of a cellular network.

In an embodiment of the autonomous discovery mechanism, the autonomousdiscovery mechanism uses the Location Areas and their identifiersprovided by, e.g., a cellular network or Public Land Mobile Network(PLMN). These include the Location Area Identity (LAI) and Cell GlobalIdentity (CGI), which are internationally unique.

These location parameters are preferably broadcast on a BroadcastControl Channel (BCC or BCCH) in a cellular network and are used by theMS's cellular network interface for mobility management in the cellularnetwork. The downlink channel contains specific parameters needed by amobile in order that it can identify the network and gain access to it.Typical information includes the LAC (Location Area Code) and RAC(Routing Area Code), the MNC (Mobile Network Code) and BA (BCCHAllocation) list. The Subscriber Identity Module in the MS stores theseparameters and updates them periodically as the MS traverses the cellsof a cellular network. The Subscriber Identity Module is abbreviated as“SIM”.

While a SIM card is generally used for GSM networks, a UniversalSubscriber Identity Module (USIM) card can involve a multi-applicationchip card that supports multiple telecommunication applications, suchas, e.g., both the internationally standardized W-CDMA format and theGSM format. So, while, e.g., a GSM format mobile phone may use an ICchip-embedded removable card called a SIM Card, which can, e.g.,contains various information required for mobile communication, such as,e.g., the mobile phone's number, and allows the same phone number to beused seamlessly in any region that's covered by the GSM network, a USIMcard can include an upgraded SIM card that is also compatible with theW-CDMA world standard. The computer chip inside the MS stores phonenumbers, address book and other information. In this disclosure, theabbreviation “(U)SIM” is inclusive of USIM, ISIM and SIM.

The (U)SIM, which is specific to the cellular network, also stores usersubscription data for identifying a user to network, and as previouslynoted, users' personal information, such the user's phone book, etc.Using the proposed autonomous discovery mechanism, the network discoverysoftware in the MS retrieves LAI and CGI from the (U)SIM and makes useof them.

LAI includes Country Code (3 decimal digits), Mobile Network Code (2decimal digits) and Location Area Code (maximum of 5 decimal digits).Thus, LAI=CC+MNC+LAC. The LAI stored on (U)SIM is periodically comparedwith that of the recent broadcast on BCCH and any change of LocationArea initiates a location update request to the network.

A Location Area may be a large geographical area. As illustrated in FIG.1, within, by way of example, a public land mobile network (PLMN), aLocation Area 10 typically involves multiple cells 20. As also shown inFIG. 1, a plurality of Location Areas 10 are typically covered by oneMobile Switching Center (MSC) 30/(Visitor Location Register (VLR) area).Typically, each cell 20 is identified by an identification number calledCell Global identity (CGI). CGI is comprised of Location Area Code andCell Identity. Thus, CGI=CC+MNC+LAC+Cell ID. CGI is also stored on(U)SIM, but updated when the mobile is in active mode.

It is anticipated that several independent WLANs can be, in someexamples, operating in the geographical area covered by a singlecellular cell. These WLANs broadcast their identifiers, for example, theService Set IDs (SSIDs) that uniquely identify each Access Point in aWLAN. A MS that is capable of listening to these broadcast/parameters,can retrieve additional information such as Realm Part, Signal Strength,etc., from the SSIDs, in addition to information about the WLANs. In thepreferred embodiments, an algorithm of the present invention listens tothe WLAN broadcasts and stores the parameters, exclusively mapped withLAI and CGI along with signal strength and time stamp.

In some embodiments, the present invention can be configured to performat least some of the following main functions:

-   -   1) Recording a recent history of movements of a MS;    -   2) Recording the WLANs traversed in the movement pattern;    -   3) Storing information about these WLANs specifically mapped        with LAI and CGI, and down selecting the most suitable candidate        network based on CGI while the session is going on;    -   4) Acquiring a local IP address from a selected target network;    -   5) Performing pre-authentication with the selected network and        making the target network available for the possible handover;    -   6) Recording a log of performance of the networks used; and    -   7) Enabling the user to prioritize the available candidate        networks based on the user's personal preferences for future        use. In some embodiments, this will populate a table, such as,        e.g., shown in FIG. 5. This stored/advance knowledge mapped with        LAI/CGI can help in proactively deciding the next attachment        point, reduce the network detection time, and consequently the        vertical handover time. Because signal strength is also        preferably stored with timestamp, it can also contribute to        reduce physical layer (PHY) measurement timing, and help        prioritize the best from the potential candidate networks.

An LA is often a large physical area (as, for example, several miles indiameter), and, for example, hundreds of WLANs may exist in thattrajectory. On the other hand, a Cell is typically a much smaller area(such as, e.g., few hundred yards in dense urban areas, around 3 milesin less dense urban areas and around 10 miles in rural areas or highwayspassing through rural areas), and fewer WLANs will fall in thetrajectory of a cell. The smaller cell area makes CGI attractive forkeeping track of the WLAN locations. A MS receives periodic updates onLAI from the cellular network regardless of the mode it operates in, butonly receives updates on CGI when it is in either Active mode(communicating) or Awake Mode (receiving short messages from thenetwork). Therefore, to obtain updates on CGI anytime the MS wants theinformation, the MS can send a dummy SMS message to, for example, itsown mobile device. Sending SMS messages updates the CGI in the (U)SIM ofthe MS. SMS refers to short message service, and includes sending smalltext messages to cell phones.

The access to a WLAN could, e.g., be free or based on servicesubscriptions with an Internet Service Provider (ISP) or a CellularService Provider (CSP). A CSP is also commonly referred to as a PLMNOperator. User authentication with an ISP usually requires username andpassword. User authentication with a PLMN Operator, on the other hand,may be done by, e.g., a (U)SIM on the MS or the like without a humanuser's intervention.

In an example embodiment, the MS has a subscription with a PLMN Operatorso that it can use the cellular network, and, therefore, the MS isequipped with a (U)SIM card. When the PLMN Operator also provides WLANs,the user's PLMN subscription may also allow the user to access the WLANsoffered by the PLMN Operator. In addition, the MS may also have servicesubscription with an ISP for using other WLANs.

With reference to FIG. 2, the selection of a WLAN will be described. Insome preferred embodiments, from the available WLANs, selection of aWLAN may be based on user's preferences. The User's preferences may varyfrom user to user or from time to time even for the same user. One suchselection criterion is to prefer a WLAN that is capable of interworkingwith cellular and also have a roaming agreement with the user's homecellular network.

In the example of FIG. 2, a cell C of a cellular system is shown inwhich a mobile station WLAN MS is located which may communicate with atleast some of four WLANs (WLAN-1, WLAN-2, WLAN-3, and WLAN-4) that areoperating within the cell C. In particular, FIG. 2 depicts a 3G-WLANinterworking model, including illustrative 3G PLMN networks, 3G PLMN-1,3G PLMN-2, 3G PLMN-3 and 3G PLMN-4. From the administration point ofview, these four WLANs may be owned by a variety of entities, such as,by way of example only:

-   -   1) Cellular (PLMN) operators;    -   2) ISP;    -   3) Hotspot Service Providers, but not necessarily ISPs (such as,        e.g., an airport authority, a restaurant, such as, e.g.,        McDonalds™, Starbucks™, etc.); and/or    -   4) Corporations for use, e.g., primarily by employees and        potentially by visitors.

With respect to Authentication, the WLANs illustrated in FIG. 2 maysupport, among other things, either:

-   -   1) Open Access Control: enabling a MS to have access to free        services (e.g., uses 802.11 open authentication);    -   2) Universal Access Control: enabling a MS to have access to        chargeable services (MS authenticated by PAC Gateway); or    -   3) 802.1X Access Control: enabling a MS to have access to        chargeable services (MS authenticated via EAP method).

From an interworking point of view, some WLANs may be connected to PLMNsand some may not, such as, e.g., shown in the example illustrated inFIG. 2. A PLMN may be a Home PLMN (HPLMN) or Visited PLMN (VPLMN). HPLMNis the network in which the subscribers' profile is held, whereas aVPLMN is a network in which the mobile subscriber has roamed whenleaving their HPLMN. Subscribers roaming to other networks will receivesubscription information from the HPLMN.

Preferably, each WLAN broadcasts a Service Set Identifier (SSID) thatserves as a WLAN identifier. The MS shown in FIG. 2 can receive signalsfrom four WLANs. Assume PLMN-1 is the HPLMN of MS. If selection criteriamandates to pick the WLAN which is capable of interworking with cellularand also have a direct or indirect roaming agreement with his homecellular network, the first preference is to select WLAN-1 because it iscapable of interworking and also has direct agreement with HPLMN(without involving any roaming partner or intermediary). In the absenceof this choice, the second preference should be to select WLAN-4 becauseit is capable of interworking and also it has roaming agreement withHPLMN (even though indirect through PLMN-3). In this example, this isshown by the connection line between 3G PLMN-1 and 3G-PLMN-3 in FIG. 2.It should preferably not select WLAN-3 as it does not have direct orindirect roaming relation with HPLMN. In this example, this is shown byno connection line between 3G PLMN-1 and 3G-PLMN-2 in FIG. 2. Also,WLAN-2 should not be selected since it is neither capable ofinterworking, nor offer direct/indirect roaming with the HPLMN.

This selection criterion is further described in Flow Diagram-A of FIG.3. When no available WLAN meets the user's selected criterion, thesorting processor may either return a message that “No Network Meets theSpecific Criterion” or may select a WLAN according to the nextpreference criterion (Security, Cost, Performance, etc.). These arediscussed further below in this document.

Flow Diagram A of FIG. 3 shows that SSID can have two different types offormats in some embodiments: a) a legacy type; and b) an advanced type,such as, e.g. (WLAN_NAME:PLMN:MCC:MNC). See, for example, the followingdocument “3GPP PLMN Selection for 802.11 Type of WLAN” 3GPPT-doc-S2-031430. The disclosure of which is incorporated here byreference in its entirety, as though recited in full. From the advancedSSID, the MS can easily find if:

-   -   1) The WLAN is the one with which the subscriber has a        subscription (comparing WLAN_NAME);    -   2) The WLAN provides interworking with PLMN (detecting the word        PLMN in the SSID);    -   3) The WLAN provides interworking with home PLMN (comparing        mobile country code MCC and Mobile Network Operator's code MNC);        or    -   4) The WLAN has direct or indirect roaming relationship with his        home PLMN (comparing with SSIDs provisioned in MS client).

However, if the SSID format is of the legacy type, a MS may not be ableto use the SSID to recognize the PLMN. In this case, an alternate methodproposed in, F. Adrangi et al., “Mediating Network Discovery andSelection”, Internet draft,draft-adrangi-exp-network-discovery-and-selection-01, February 2004, canbe used. The disclosure of Adrangi, et al., is incorporated herein byreference in its entirety, as though recited in full. According to thismethod, the MS sends a Decorated NAI in the Type-Data field of the“EAP-Identity Response” asking the WLAN if it supports his HPLMN or itspreferred roaming partner, and in turn gets the answer in the“EAP-Identity Request” message. Upon receipt of the information, the MSthen may select a preferred WLAN or store the information received forfuture use.

In another embodiment, the MS sends a simple query probe and in responsereceives XML metadata including information about the PLMNs interworkingwith this WLAN. This embodiment of the invention requires continuallyprobing for each SSID. This might be burdensome from the powerconsumption point of view, in addition to adding extra delays. However,in this embodiment, the MS preferably probes networks only until thepredetermined minimum battery condition is reached.

Referring to FIG. 3, it can, thus, be seen that this figure demonstratesillustrative functionality that can be implemented by the mobile device(note: all functionality of the mobile device may be implemented insoftware, hardware, firmware and/or the like as appropriate or desiredunder the circumstances) in the retrieving of parameters, e.g., forpopulating a table or the like as shown in FIG. 5 without requiring aconnection to any network.

As shown, at a step 310, the system starts with a check for an activesession. As step 320 a determination is made if a session is on. If theanswer is yes, at step 325, the process gets both LAI and an updated CGIfrom (U)SIM by sending a dummy SMS to itself, and then listens to SSIDsand picks one in step 340. If the answer is no, at step 330, the processgets the LAI from the (U)SIM, and then listens to SSIDs and picks one instep 340. Then, at step 350 a determination is made if the SSID belongsto format type-1. If the answer is no, then the MS sends a probe andgets the SSID at step 355. Then, from either step 350 or 355 uponacquiring the SSID, a decision is made at 360 if such is already in thedatabase. If the answer is yes, the system returns to step 340 to againlisten to SSIDs and pick one. Otherwise, if the answer is no, theprocess proceeds to step 370, at which point a decision is made, in somepreferred embodiments, as to whether the SSID belongs to the Home PLMN.If the answer is yes, then the process goes to step 375 and stores theSSID and retrieves parameters in Category A of Table-1 shown in FIG. 5after mapping with LAI and CGI. Otherwise, if the answer is no, then theprocess proceeds to step 380, at which point a decision is made, in somepreferred embodiments, as to whether the SSID belongs to the Home PLMN'sroaming partners. If the answer is yes, then the process goes to step385 and stores the SSID and retrieves parameters in Category B ofTable-1 shown in FIG. 5 after mapping with LAI and CGI. Otherwise, ifthe answer is no, then the process proceeds to step 386 and stores theSSID and retrieves parameters in Category C of Table-1 shown in FIG. 5after mapping with LAI and CGI. At which point, an evaluation of thebattery power remaining is made at step 390. If there is less than athreshold level (such as, e.g., 75% in the example), then the processproceeds to confirm by step 400 if the user's preference criteria mayhave changed, and, if so, a trigger is sent to the sorting unit at step410, and, if not, the process proceeds to stop. On the other hand, ifthe battery power is above the threshold (e.g., over 75%), then thesystem proceeds back to step 310.

Although FIG. 2 and FIG. 3 show a network environment, generalized forWLAN and cellular networks, other types of networks and otherinterworking can also be employed in other embodiments. For example, inaddition to common cellular networks such as, e.g., those used in mobiletelephone usage that provide connectivity, e.g., to Public SwitchedTelephone Networks (PSTN), the networks providing location informationcan include in some embodiments any appropriate network having cellareas (i.e., geographical areas). In addition, in other embodiments,other network selection criteria based on, for example, Pricing,Performance, and Security, may also be used.

As discussed above, the network information collected over time ispreferably stored in any appropriate format. An example of a table orlist populated with data is shown in FIG. 5. Preferably, the tablestores network parameters mapped with LAI and CGI. Preferably, thecolumns are constructed based on predetermined criterion. By way ofexample, for illustrative purposes, a column designated as “Category A”evaluates and prioritizes the available WLANs in a given CGI based on“WLAN-PLMN interworking” criterion. On the other hand, the columndesignated as “Category B” evaluates and prioritizes the available WLANsin a given CGI based on “WLAN-PLMN Direct Roaming Agreement” criterion.In addition, the column titled “Category C” evaluates and prioritizesthe available WLANs in a given CGI based on “WLAN-PLMN Indirect RoamingAgreement” criterion. In some preferred embodiments, these columns arefilled in according to an algorithm illustrated in Flow Diagram 1 shownin FIG. 3.

Additionally, the information about performance parameters can becollected, and a log of network behavior and performance when a MS fullyconnects to the network, can be generated. With reference to the flowdiagram shown in FIG. 4, this figure explains, e.g., an algorithm forgetting information on these parameters and populating columnsdesignated as D, E, and F of the sample Table shown in FIG. 5. Columnsdesignated as “Category D,” “Category E,” and “Category F” evaluate andprioritize the available WLANs in a given CGI based on “Security”,“Performance,” and “Cost” criteria, respectively.

This gives the mobile an opportunity to gradually learn about theperformance of various networks and helps a user to prioritize thenetwork based on the information collected.

With reference to FIG. 4, functionality that can be employed by themobile device is depicted, which can be used to, e.g., populate theTable-1 shown in FIG. 5 when the mobile station is connected to anetwork. First, at step 410, the process can get both the LAI and theCGI from the (U)SIM card. Then, at step 420, the process can pick theprioritized SSID from a sorted Table or the like (such as, e.g., shownin FIG. 5), then the mobile device can log into the network using thatSSID as shown at step 430. Then, as shown at step 440, the mobile devicecan use the network. Then, based on such usage, additional informationcan be obtained. For example, as shown at step 450, the system canpreferably obtain performance related parameters (such as, e.g., Signalto Noise Ration (SNR), Signal Strength, etc.), and, then, the processcan go to step 455 to store and update information in Category D ofTable 1 after mapping with LAI and CGI. As another example, as shown atstep 460, the system can preferably obtain security related parameters(such as, e.g., Open Access Control, Universal Access Control, 802.1XAccess Control, etc.), and, then, the process can go to step 465 tostore and update information in Category E of Table 1 after mapping withLAI and CGI. As yet another example, as shown at step 470, the systemcan preferably obtain cost related parameters (such as, e.g., Free, CostPer Minute, etc.), and, then, the process can go to step 475 to storeand update information in Category F of Table 1 after mapping with LAIand CGI.

In an embodiment of the invention, a sorting mechanism that can sort thecolumns of the sample table based on user's preferred selection criteriacan be employed. For example, if a user prefers to always connect to themost secure network, the sorting mechanism can prioritize the availablenetworks by sorting column D and picking the SSID that has a greaterweight in Column D, disregarding other columns.

In some embodiments, the SSID selection can be based on a singleselection parameter (e.g., Security only), a double selection ofparameters (e.g., Security and interworking), or on more selectionparameters (e.g., Security, Performance and interworking). Thus, thecolumns of the sample table can be sorted based on simple (one selectionparameter) or complex (combination of several parameters) methods. Insome embodiments, user preferences can be input by a user through a UserInterface (e.g., user entry via a graphical user interface, keyboard orthe like) or an Application Interface (API) (e.g., computer entry via asoftware application or the like). They can also be preconfigured by theoperator into the terminal or the USIM or the like.

Regardless of which selection criteria a user adopts, the mobile deviceis preferably be able to use the learned information to perform thefollowing processing before it needs to handoff from one network toanother, as for example a) cellular to WLAN, or b) one WLAN to another:a) detect the available networks; and b) perform authenticationprocedures.

In some preferred embodiments, the MS can look at its current LAI/CGI,use it as the index to look up a table, such as shown in FIG. 5, toquickly select one preferred candidate network from the list of networksstored in the table (priority-wise and mapped with LAI and CGI), andattach to the selected network promptly.

In some examples, a MS may know more about some WLANs than other WLANsat any given time. For example, the MS may have learned about a WLAN Xfrom only the radio beacons received from the WLAN X, but may have neverused the WLAN X and hence not have any upper layer information on, andexperience with, the WLAN X. On the other hand, after using a WLAN Y,the MS can learn more about WLAN Y than WLAN X. However, the WLAN X maybe a much better choice for the user in some examples.

Accordingly, in some embodiments, in order to ensure that the MS willgive WLAN X a chance, a process of change governed by probabilities canbe employed. In the preferred embodiments, a weight is assigned to eachknown WLAN. Preferably, the weight assigned to a WLAN reflects the“goodness” of the WLAN for satisfying the user's requirements andpreferences, based on the information the MS collected about the WLAN sofar. The better the WLAN, the higher the weight assigned. Every time,the MS acquires new information about a WLAN, it uses the newinformation to adjust the weight assigned to the WLAN. For example, ifthe MS just used the WLAN and found out that the quality of services(QoS) over the WLAN dropped significantly compared with the QoS when theMS used the WLAN last time, then the MS will reduce the weight assignedto the WLAN.

In some embodiments, the selection algorithm can make selectiondecisions based on the weights assigned to the known WLANs that the MSmay move into next. For example, where W_(i) is the weight assigned toWLAN i and there are k WLANs surrounding the MS at this moment, then,the MS can select the j^(th) WLAN from these k WLANs with probabilityp_(j) which is calculated as follows:

$p_{j} = \frac{W_{j}}{\sum\limits_{i = 1}^{k}W_{i}}$where W=assigned weight value, P_(j)=probability, k=number of WLANSwithin said mobile station's current cell area, W_(i)=the weightassigned to WLAN i, and W_(j)=the weight assigned to WLAN j. In otherembodiments, a variety of other methodologies may be employed.

Referring again to FIG. 5, the figure demonstrates overall functionalitythat may be implemented within the mobile station according to somepreferred embodiments of the invention. In this regard, FIG. 5illustrates that data or information can be stored within the mobilestation (such as, e.g., within a database, digital data storage or thelike) which can be depicted, for illustrative purposes, in the form of aTable as shown in some illustrative examples, which data can includeSSID information mapped to (e.g., corresponded or correlated to)location information (e.g., LAI and/or CGI information as shown). Inaddition, as shown, the data can include a variety of Categories ofdata, some of which data may be available for some and not othernetworks at any given time (as discussed above). In addition, the datacan include data obtained, in the preferred embodiments, from one of two(preferably both) processes—i.e., a process of obtaining informationwithout connection to a network (such as, e.g., shown in FIG. 3 in whichthe mobile device listens to broadcasts of SSIDs or the like), and aprocess of obtaining information during connection to a network (suchas, e.g., shown in FIG. 4 in which the mobile device actually picks anetwork and attaches to it and obtains additional information based onuse of that network.

Last, FIG. 5 also depicts a user input (which can be via a keyboard,user interface or the like) or which can be via an API as shown in FIG.5 which input is used by a processor for sorting the table according touser preference as schematically indicated in FIG. 5. As a result, themethodologies for selection can be varied based on user preferences insome preferred embodiments of the invention.

While a number of illustrative examples have been described above, itshould be appreciated based on this disclosure that these are merelyillustrative embodiments as explained below.

BROAD SCOPE OF THE INVENTION

While illustrative embodiments of the invention have been describedherein, the present invention is not limited to the various preferredembodiments described herein, but includes any and all embodimentshaving equivalent elements, modifications, omissions, combinations(e.g., of aspects across various embodiments), adaptations and/oralterations as would be appreciated by those in the art based on thepresent disclosure. The limitations in the claims are to be interpretedbroadly based on the language employed in the claims and not limited toexamples described in the present specification or during theprosecution of the application, which examples are to be construed asnon-exclusive. For example, in the present disclosure, the term“preferably” is non-exclusive and means “preferably, but not limitedto.” In this disclosure and during the prosecution of this application,means-plus-function or step-plus-function limitations will only beemployed where for a specific claim limitation all of the followingconditions are present in that limitation: a) “means for” or “step for”is expressly recited; b) a corresponding function is expressly recited;and c) structure, material or acts that support that structure are notrecited. In this disclosure and during the prosecution of thisapplication, the terminology “present invention” or “invention” may beused as a reference to one or more aspect within the present disclosure.The language present invention or invention should not be improperlyinterpreted as an identification of criticality, should not beimproperly interpreted as applying across all aspects or embodiments(i.e., it should be understood that the present invention has a numberof aspects and embodiments), and should not be improperly interpreted aslimiting the scope of the application or claims. In this disclosure andduring the prosecution of this application, the terminology “embodiment”can be used to describe any aspect, feature, process or step, anycombination thereof, and/or any portion thereof, etc. In some examples,various embodiments may include overlapping features. In thisdisclosure, the following abbreviated terminology may be employed:“e.g.” which means “for example.”

1. A method, comprising: having a mobile device perform discovery anduse of target wireless networks which are at least partly within acoverage area of another wireless network that is heterogeneous to saidtarget wireless networks which provides location information, includinghaving the mobile device autonomously perform: acquiring data from aplurality of said target wireless networks and storing said data locallywithin the mobile device for network discovery; acquiring locationinformation from said another wireless network and storing said datalocally within the mobile device for network discovery; mapping saiddata from said plurality of said target wireless networks with saidlocation information; and selecting one of said plurality of targetwireless networks based on said mapped data.
 2. The method of claim 1,further including having at least some of said target wireless networksoperated by a same entity as said another wireless network or by anotherentity having a roaming agreement with said same entity.
 3. The methodof claim 1, wherein said target wireless networks include wireless localarea networks, and said acquiring of data from at least one of saidtarget wireless networks includes receiving wireless local area networkbroadcasts from said wireless local area networks.
 4. The method ofclaim 1, wherein said another wireless network includes a cellularnetwork or a public land mobile network having a plurality of basestations which each wirelessly transmit within a particular cell area.5. The method of claim 1, wherein said acquiring location informationincludes acquiring location information from said another wirelessnetwork when said mobile station is not in an active mode with saidanother wireless network.
 6. The method of claim 5, wherein saidacquiring location information includes obtaining and storing CGIinformation even when the mobile device is in an idle mode.
 7. Themethod of claim 1, wherein said selecting is based at least in part onstored user preferences.
 8. A system, comprising: a mobile deviceadapted for discovery and use of target wireless networks which are atleast partly within a coverage area of another wireless network that isheterogeneous to said target wireless networks which provides locationinformation, further including: said mobile device being configured toacquire data from a plurality of said target wireless networks and tostore said data locally within the mobile device for network discovery;said mobile device being configured to acquire location information fromsaid another wireless network and to store said data locally within themobile device for network discovery; said mobile device being configuredto map said data from said plurality of said target wireless networkswith said location information; and said mobile device being configuredto select one of said plurality of target wireless networks based onsaid mapped data.
 9. The system of claim 8, further including at leastsome of said target wireless networks being operated by a same entity assaid another wireless network or by another entity having a roamingagreement with said same entity.
 10. The system of claim 8, furtherincluding said target wireless networks include wireless local areanetworks, and said acquiring of data from at least one of said targetwireless networks includes receiving wireless local area networksbroadcasts from said wireless local area networks.
 11. The system ofclaim 8, wherein said another wireless network includes a cellularnetwork or a public land mobile network having a plurality of basestations which each wirelessly transmit within a particular cell area.12. The system of claim 8, further including said mobile device beingconfigured to acquire said location information from said anotherwireless network and to store said data locally within the mobile devicewhen said mobile station is not in an active mode with said anotherwireless network.
 13. The system of claim 12, wherein said acquiring andlocation information includes obtaining and storing CGI information evenwhen the mobile device is in an idle mode.
 14. The system of claim 5,wherein said mobile device is configured to select one of said pluralityof target wireless networks based at least in part on stored userpreferences.